JP2000333426A - Electric motor having vibration reducing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce transmission of vibration between a stator and a base. SOLUTION: In this motor A34, a plurality of members that can elastically bend are arranged between a base (tubular stem) 108 and a stator 100, in order to reduce the transmission of vibration caused to occur between them. Tubular spring pins are recommended as the members that can bend elastically, being arranged between the stator 100 and the base 108. Each of the tubular spring pins has a cylindrical sidewall that partitions a slot. While this motor 34 is in operation, the vibration generated inside the stator 100 causes the sidewall of the spring pins to bend elastically, thereby reducing the vibration. The spring pin is arranged between the stator 100 and the tubular stem 108.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor for damping transmission of vibration between a stator and a base.

[0002]

2. Description of the Related Art Known electric motors include a magnetic field assembly or stator surrounded by an armature assembly or rotor. A shaft is connected to the rotor and extends through the stator. O-rings are placed between the components of the stator to provide vibration isolation. An electric motor having this structure is disclosed in US Pat.
No. 5,227. Other known electric motors are disclosed in U.S. Pat. Nos. 4,082,974 and 5,315,200.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric motor that attenuates the transmission of vibration between a stator and a base.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an electric motor having a base and a stator connected to the base. The rotor can rotate with respect to the stator by the action of the magnetic force transmitted between the rotor and the stator. In order to reduce the transmission of vibration between the stator and the base, an elastically deflectable member is arranged between the stator and the base. The resiliently flexible member may be a spring pin.

[0005] These and other features of the present invention will become more apparent to those skilled in the art to which the present invention pertains from a reading of the following description of the invention with reference to the accompanying drawings.

[0006]

DETAILED DESCRIPTION OF THE INVENTION An apparatus 30 for use in pumping hydraulic fluid is shown schematically in FIG. One particular preferred embodiment of the device 30 is shown in FIG. Apparatus 30 (FIGS. 1 and 2)
Can be used in many different environments, but the device
It is believed that it is particularly suitable for supplying power steering fluid to a hydraulic assisted rack and pinion steering device. Device 30, when used in conjunction with a rack and pinion steering device, provides fluid pressure to operate a power steering motor in response to operation of a vehicle steering wheel. Actuation of the power steering motor causes the steerable wheels of the vehicle to rotate in a known manner.

[0007] Apparatus 30 includes a pump unit 32 driven by an electric motor 34 formed in accordance with the present invention. The drive shaft 36 transmits the torque (torque) from the electric motor 34 to the pump unit 32. The drive shaft 36 includes an input shaft 38 to the pump unit 32 and an output shaft 40 from the electric motor 34. The input shaft 38 of the pump unit and the output shaft 40 of the electric motor are arranged in a coaxial relationship.
(See FIG. 2).

The rigid metal manifold plate 44 (FIG. 1)
And FIG. 2) shows the pump unit 32 and the electric motor 34.
And are connected to them. Drive shaft 36 extends through manifold plate 44. Hydraulic fluid is directed through the manifold plate 44 to and from the pump unit 32. During operation of the hydraulic muffler pump unit 32 (see FIGS. 1 and 2), noise is generated due to pressure fluctuation of the hydraulic fluid generated by the pump unit. To attenuate noise, an inlet to the pump unit 32 and a reservoir 52 for holding hydraulic fluid (FIG. 1)
And muffler 50) (see FIG. 1).
Can be provided. The reservoir 52 is formed by a translucent polymer housing 54 connected to the manifold plate 44 (see FIG. 2). Reservoir 5
The hydraulic fluid in 2 is exposed at the inlet end 56 of the hydraulic muffler 50.

[0009] The hydraulic muffler 50 includes a channel 58 formed in the manifold plate 44. The channel 58 has a serpentine configuration and provides hydraulic fluid to the hydraulic muffler 50.
To the exit end 60. The flow of the hydraulic fluid in the channel 50 is effective in attenuating the noise generated by the pump unit 32.

The outlet end 60 (see FIG. 1) of the hydraulic muffler 50 is located adjacent to an opening 62 formed in the manifold plate 44 and is in fluid communication with the opening. An input shaft 38 to the pump unit 32 extends into the opening 62 and is connected to an output shaft 40 from the electric motor 34 at the opening. Hydraulic fluid from the channel 58 passes from the opening 62 along the inlet shaft 38 of the pump unit 32 to the pump unit 32.
Flows into the entrance opening to.

The pump unit 32 is a part of the pump assembly 64. The pump unit 32 is located in a pump chamber 66 (see FIG. 1) formed in a rigid metal body section 68 of the pump assembly 64. One end of the main body section 68 is provided with a metal rigid lower cover plate 70.
Has been closed by. The opposite end of the body section 68
It is closed by a metal rigid upper cover plate 72.

During operation of the pump unit 32 in the pump chamber 66 of the body section 68, the pump unit flows hydraulic fluid from the reservoir 52 to the inlet end 56 of the hydraulic muffler 50. The hydraulic fluid then flows along channel 58 to outlet end 60 and opening 62 of hydraulic muffler 50.
Hydraulic fluid then flows along the drive shaft 36 through the inlet opening 76 in the lower cover plate 70. Hydraulic fluid flows from inlet opening 76 to the inlet to pump chamber 66 and pump unit 32.

During operation of the pump unit 32, high pressure fluid is directed from the pump chamber 66 toward the inside of the upper cover plate 72. The high-pressure fluid discharged from the pump unit 32 passes through a recess (not shown) formed inside the upper cover plate 72 to the outside of the pump chamber 66.
Through an outer body section 68 into a resonator passage 82 extending axially. The high pressure fluid from the resonator passage 82
It is collected in a recess 84 formed inside the lower cover plate 70.

The high pressure fluid is directed from the recess 84 through one outlet passage 86 in the lower cover plate 70 to an outlet passage 88 formed in the manifold plate 44. The high pressure fluid is directed from the outlet passage 88 through an opening 90 formed in the cylindrical outside 92 of the manifold plate 44. When the device 30 is used in conjunction with a vehicle power steering system, high pressure fluid is directed from the opening 90 through an outlet conduit 94 (see FIG. 2) to a power steering control valve. This valve is activated in response to turning the vehicle's steering wheel. Electric Motor An electric motor 34 (see FIGS. 1 and 2) is operable to drive the pump unit 32. The electric motor 34 includes a generally cylindrically shaped stator 100. The stator 100 includes a plurality of windings 102 arranged in an annular array about a central longitudinal axis of the stator. Stator 100 has a cylindrical central passage 106 (see FIG. 1) that extends axially through the stator.

The stator 100 is mounted on a cylindrical tubular stem 108 that extends axially outward from the manifold plate 44 in a direction away from the pump unit 32. The tubular stem 108 forms the base of the electric motor 34. The stator 100 includes the stem 1
08 are nested outside and are connected to the stem. The central axis of the stator 100 coincides with the central axis of the tubular stem 108 and the drive shaft 36.

The cylindrical tubular stem 108 and the manifold plate 44 are integrally cast as one piece of metal and form a base 110. Although one particular base 110 is illustrated in FIGS. 1 and 2, the base may have a different structure if desired.

A cylindrical rotor 112 extends outside the stator 100. The rotor 112 is connected to the stator 10
0 is surrounded. The cylindrical rotor 112 is a stator 1
00 and a stem 108 that forms the base of the motor 34.

The rotor 112 includes a circular array of permanent magnets 113. These permanent magnets 113 are firmly fixed to the cylindrical housing 114. The housing 114 has a circular end wall 117 to which the cylindrical side wall 115 and the motor output shaft 40 are securely connected.
(See FIG. 2). The rotor 112 is
Rotate about the central axis of. The central axes of the rotor 112 and the stator 100 coincide with the longitudinal central axis of the tubular stem 108. The electric motor 34 is attached to the base 110 on the side opposite to the pump unit 32.

A cylindrical motor output shaft 40 is rigidly connected to the axial end of the rotor 112 furthest from the manifold plate 44. Output shaft 4
0 denotes the cylindrical passage 106 of the stator 100 and the base 1
It extends axially through ten stems 108. The motor output shaft 40 is connected to the pump input shaft 38 at an opening 62 in the manifold plate 44.

The motor output shaft 40 and the rotor 112
Is rotatably supported by a pair of bearings 126 and 128 (see FIG. 2). These bearings 126 and 128 are located within the cylindrical passage 130 of the tubular stem 108 forming the base of the motor 34. Bearings 126 and 128 rotatably support motor output shaft 40 for rotation relative to stator 100 about tubular stem 108 and center axis 134 of stator 100. Axis 134
Coincide with the central axis of the motor output shaft 40, the central axis of the tubular stem 108, the central axis of the stator 100, and the central axis of the rotor 112. Seal 138 blocks the upper portion of passage 130.

The motor control circuit 116 controls the support plate 11
8 attached. The motor control circuit 116 is disposed between the manifold plate 44 and the stator 100. The motor control circuit 116 controls the electric motor 34
Controls the operation of. A flexible coupling is provided between the motor control circuit 116 and the stator 100 to minimize vibration forces transmitted to and through the motor control circuit.

When operating the apparatus 30 to supply pressurized fluid, the motor control circuit 116
Energize. This causes the rotor 112 and the output shaft 40 to rotate about their coincident central longitudinal axis. This drives the pump unit 32 to provide pressurized hydraulic fluid.

The electric motor 34 includes a stator 100 and at least a part of the base of the motor, that is, the tubular stem 1.
08 is formed to have a rotor 112 surrounding the same. However, the electric motor 34 may be formed so that the stator surrounds the rotor. Electric motors in which the stator surrounds the rotor are well known and are disclosed in US Pat. No. 4,082,974 and / or US Pat.
It has a structure similar to the structure disclosed in US Pat. No. 5,200.

In an exemplary embodiment of the invention, base 110
Are cast as one piece of metal. Base 110 may be formed of a plurality of tightly interconnected components. For example, the manifold plate 44
And the tubular stem 108 may be formed separately from each other and then firmly interconnected with each other.

The illustrated base 110 includes the pump unit 3
Manifold plate 4 that guides fluid through during operation of 2
4 inclusive. However, the base 110 may be formed as a solid block with or without the tubular stem 108 and corresponding extensions. If desired, motor 34 may include a base other than tubular stem 108. Although it is preferred to use a motor 34 to drive the pump unit 32, the motor 34 can be used to drive other known devices, if desired.

Apparatus 30 is disclosed in US patent application Ser. No. 09 / 198,126, filed on Nov. 23, 1998, entitled "Pump with Muffler for Attenuating Noise" filed by George Harpole et al. No. 5215) has the same overall structure as disclosed in US Pat. However, it should be understood that the device 30 may vary in construction and can be used for many different purposes if desired. Vibration Isolation In accordance with a feature of the present invention, members 144 and 146 (see FIGS. 3 and 4) that can flex elastically
0 and the tubular stem 108 of the base 110. During the operation of the electric motor 34 (see FIGS. 2 and 3), the stator fluctuates due to torque fluctuation at the interface between the rotor 112 and the stator 100. If the elastically flexible members 144 and 146 are not provided, vibration is transmitted through the base 110 to the housing 54 that forms the reservoir 52 and surrounds the pump assembly 64.

Unpleasant noise is generated by vibration of the base 110 and / or the housing 54. Electric motor 34
Is related to devices other than the pump assembly 64 and the housing 54, the vibration generated in the base is considered to be unpleasant. Elastically flexible member 14
4 and 146 reduce the transmission of vibration from the stator 100 to the base of the motor 34, thereby minimizing unpleasant noise during operation of the electric motor.

In the embodiment of the present invention shown in FIG. 4, the members 144 and 146 which can be elastically
00 and a tubular stem 108 forming the base of the electric motor 34. If desired, electric motor 34 may include a base other than tubular stem 108. In FIG.
It should be understood that the windings 102 have been omitted to clearly illustrate the relationship between the resiliently flexible members 144 and 146 and the tubular stem 108.

The frame 150 is provided with the tubular stem 10.
8 has a cylindrical central portion 154 extending around 8 and a central axis coinciding with the central axis of the tubular stem 108 and the output shaft 40 of the motor. A plurality of arms 156 extend radially outward from central portion 154 of frame 150. These arms 156 extend axially over the length of the stator 100. Although the winding 102 (see FIGS. 1 and 3) is omitted in FIG.
It should be understood that 02 is provided around each of the arms 156 of the stator frame 150. Stator frame 150 is integrally formed as a single metal part.

Resiliently deflectable members 144 and 146 are disposed between the cylindrical inner surface 160 of the central portion 154 of the stator frame 150 and the cylindrical outer surface 162 of the tubular stem 108. I have. The resiliently flexible members 144 and 146 are arranged parallel to an axially extending linear groove 166 formed in the central portion 154 of the stator frame 150. Further, the resiliently deflectable members 144 and 146 are disposed parallel to the axially extending linear grooves 168 formed in the tubular stem 108.

The side surface of the groove 166 of the stator frame 150 has a center of curvature that is the cylindrical inner surface 1 of the stator frame.
It is arranged radially inward from 60. Each groove 166
Are formed as one segment of a cylinder, 18
It extends over an angle range of 0 ° or less. Similarly, the sides of the groove 168 of the tubular stem 108 have a center of curvature located radially outward from the cylindrical outer surface 162 of the stator tubular stem. Each of the grooves 168 is formed as a segment of a cylinder and extends over an angular range of 180 ° or less. The central longitudinal axis of the straight grooves 166 and 168 is the motor output shaft 4.
0 extends parallel to the longitudinal central axis 134 (see FIG. 3).

Resiliently flexible members 144 and 146 are located in grooves 166 and 168 in stator frame 150 and tubular stem 108. The elastically deflectable members 144 and 146 are provided in the grooves 16.
6 and 168 have corresponding linear features. The central longitudinal axis of the resiliently deflectable members 144 and 146 extends parallel to the corresponding central longitudinal axis of the central portion 154 of the stator frame 150 and the central longitudinal axis of the tubular stem 108. ing. The central axes of the elastically deflectable members 144 and 146 are located in a plane that includes the longitudinal central axis of the tubular stem 108.

During operation of the electric motor 34, vibration forces extending tangentially and radially to the cylindrical inner surface 160 of the stator frame 150 are insulated by elastically deflectable members 144 and 146. . Accordingly, the vibration force transmitted between the stator frame 150 and the tubular stem 108 forming the base of the electric motor 34 is greatly reduced.

Resiliently deflectable members 144 and 146 securely couple the effective transmission frequency of the structure formed by stator frame 150 and tubular stem 108 to the tubular stem at the rigid key-slot connection. 10 more than the structure provided by stator frame 150
More than doubled. By reducing the vibrational forces transmitted between the stator frame 150 and the tubular stem 108 during operation of the electric motor 34, the reservoir 52
Vibrations of the manifold plate 44 and the housing 54 forming (see FIG. 2) are reduced. The vibration of the sheet metal housing 174 (see FIG. 2), which is connected to the manifold plate 44 and surrounds the electric motor 34, is also reduced. Manifold plate 44 and housing 54
And the amount of unpleasant noise during operation of the electric motor 34 is greatly reduced.

In the embodiment of the present invention shown in FIGS.
The rotor 112 surrounds the stator 100 and the tubular stem 108 that forms the base for the electric motor.
However, it is also conceivable to form the electric motor such that the stator surrounds the rotor. If this is done, the members 144 and 14 can be elastically flexed.
6 is provided between a part of the stator adjacent to the base of the electric motor.

In an exemplary embodiment of the present invention, members 144 and 146 that can be elastically flexed include stator 100
Extends in the axial direction over substantially the entire length (see FIG. 3). However, in other motor configurations, the members 144 and 146 that can be elastically deflected include the stator 10
It extends over a relatively short distance at both axial ends. Resiliently deflectable members 144 and 146
In the electric motor 34 having a different structure, the stator 100
Between the outer surface of the motor and the base of the electric motor.

According to another feature of the invention, the resiliently flexible members 144 and 146 are tubular spring pins. These tubular spring pins 144 and 1
46 is the same. The tubular spring pin 144 has a generally cylindrical shape (see FIGS. 5 and 6).

The tubular spring pin 144 has a cylindrical outer surface 180 (see FIGS. 5 and 6). Spring pin 1
The radius of curvature of the 44 cylindrical outer surface 180 is slightly smaller than the radius of curvature of the groove 166 formed in the stator frame 150. Similarly, the radius of curvature of the cylindrical outer surface 180 of the spring pin 144 is similar to that of the groove 16 of the tubular stem 108.
8 is smaller than the radius of curvature. Because the radius of curvature of the cylindrical outer surface 180 of the spring pin 144 is smaller than the radius of curvature of the grooves 166 and 168, when inserted into the grooves 166 and 168, the spring pin 144 and the surfaces of the grooves 166 and 168 are in line contact. I do. As a result, the outer surface 18 of the spring pin 144
The spring pin 144 can be flexed freely by forces acting radially and tangentially at zero.

A linear slot 184 (see FIGS. 5 and 6) extending in the longitudinal direction is formed in the cylindrical side wall 186 of the spring pin 144 to absorb the elastic deflection of the spring pin 144. The outer surface 180 of the spring pin 144 extends between opposite longitudinal sides of the slot 184.
In an exemplary embodiment of the invention, a tubular spring pin 144 is provided.
The inner surface 190 of the spring pin is centered on the outer surface 18 of the spring pin.
Coincides with the center of curvature of zero. Both ends 1 of spring pin 144
92 and 194 (see FIG. 5) are tapered in the axial direction to facilitate insertion of the spring pins into grooves 166 and 168.

When the spring pin 144 is in a relaxed state, that is, when the spring pin is unconstrained, the diameter of the cylindrical outer surface 180 of the spring pin is limited by the grooves in the stator frame 150 and the tubular stem 108. 166 and 16
8 is greater than the maximum distance between the surfaces. Thus, when the spring pin 44 is inserted into the longitudinally extending opening formed by the cooperation of the two grooves 166 and 168,
The spring pin 144 is elastically compressed. However,
The degree of elastic compression of the spring pin 144 is relatively small and not large enough to close the stator 184.

The front end portion 192 or 19 of the spring pin 144
When pushing 4 into the longitudinally extending opening formed by the two grooves 166 and 168, a force is applied to the side wall 186 of the spring pin and the slot 184 is slightly closed. As a result, the spring pin 144 exerts a force on the tubular stem and the stator frame 150 to
Is pressed radially outward in a direction away from the tubular stem 108. An elastically deflectable spring pin 146 is disposed diametrically opposite the spring pin 144. The same springs 144 and 146 apply radially offsetting forces to the stator frame 150 and the tubular stem 108, causing the cylindrical inner surface 160 of the stator frame 150 and the cylindrical outer surface 162 of the tubular stem 108 to Maintain a relatively small circular gap between them. Therefore, the stator frame 150 does not engage with the tubular stem 108.

During operation of the electric motor 34, all vibration forces transmitted from the stator frame 150 to the tubular stem 108 are resiliently deflected by spring pins 144.
And 146. Stator frame 15
The stator frame and tubular stem are spaced apart by spring pins 144 and 146, even though there is only a small gap between the cylindrical inner surface 160 of cylinder 0 and the cylindrical outer surface 162 of tubular stem 108. Is maintained. The spring pins 144 and 146 themselves flex elastically to dampen vibration forces. This minimizes vibration of the tubular stem 108 during operation of the electric motor 34.

In an exemplary embodiment of the invention, the spring pins 14
4 has a cylindrical shape. However, if desired, the spring pin 144 can be provided with a non-circular configuration. For example, the spring pin 144 can be provided with a generally polygonal feature. If the spring pin 144 is formed to have a polygonal configuration, one corner of the spring pin is located in the groove 166 of the stator frame 150 and the opposite corner of the spring pin is a tubular stem. 108 grooves 16
8 is placed. Spring pins having a generally polygonal configuration may or may not have slots corresponding to slots 184 of spring pins 144.

In the embodiment of the invention shown in FIG. 4, only two spring pins 144 and 146 are used, although it is contemplated that more spring pins could be used if desired. If more than one spring pin is used, it may be desirable to have the spring pins spaced an equal arc distance across the circular inner and outer surfaces of stator frame 150 and tubular stem 108. For example, if six identical spring pins of the same construction as spring pins 144 and 146 are used, these spring pins would be located in grooves approximately 60 ° apart around the circumference of tubular stem 108. .

The spring pins 144 and 1 shown in FIGS.
In the embodiment of 46, the length of the spring pin is approximately the same as the axial length of the stator 100. Thus, the spring pin 1
Reference numeral 44 (see FIG. 3) extends between both ends of the stator 100 in the axial direction. It is contemplated that the length of the spring pin 144 may be shorter than the length shown of the spring pin.

If desired, the length of the spring pin 144 may be
It may be equal to or less than half the axial length of the stator 100. If the axial length of the spring pin 144 is less than half the axial length of the stator 100,
A plurality of spring pins can be used instead of four. Thus, a pair of axially spaced apart spring pins are provided in the grooves 166 and 168 adjacent the axially opposite ends of the stator 100.
Can be placed inside.

The spring pin 144 (see FIG. 5) is made of metal. The spring pins 144 may be made of stainless steel or 55Si7DIN17222 steel. The special spring pin 144 has a typical diameter of about 2.0 mm and a wall thickness of about 0.2 mm. The overall length of this particular spring pin is about 21 mm.

The above specific dimensions and materials for specific spring pins 144 and 146 have been described herein for purposes of clarity and not for purposes of limiting the present invention. It should be understood that no. It is envisioned that the spring pins 144 and 146 can be formed of many different materials and many different dimensions.

As the wall thickness of the spring pins 144 and 146 decreases, the stiffness of the spring pins also decreases. The length of the thin-walled spring pins is increased to provide the required vibration isolation properties to the spring pins 144 and 146. For example, the thickness of the spring pin can be reduced to 0.15 mm and the length of the spring pin is 50 m
m. In another embodiment, two spring pins 14
Instead of using 4 and 146, four spring pins can be used. The four spring pins are approximately 25 mm in length,
The wall thickness is about 0.15 mm. Of course, the length and / or wall thickness of the spring pin can be varied as a function of the change in the material from which the spring pin is formed to obtain the desired vibration isolation properties.

The motor control circuit 116 controls the stator 100 of the electric motor 34 by a metal hook (not shown).
Can be linked to The motor control circuit 116 is also connected to the manifold plate 44. Therefore, the vibration
The electric power can be transmitted from the electric motor 34 to the manifold plate 44 through the motor control circuit 116. However, the motor control circuit 116 is connected to the stator 100 of the electric motor 34.
The hooks connecting to are made of sheet metal and are very flexible. Therefore, the vibration force transmitted from the stator 100 to the motor control circuit through the metal hook is very small. Elastically Flexible Member-Second Embodiment In the embodiment of the present invention shown in FIGS. 1-6, the elastically flexible members 144 and 146 are formed by a metallic tubular body. You. In the embodiment of the present invention shown in FIGS. 7 and 8, the elastically bendable member is formed of a sheet metal part wound in a roll shape. Since the embodiment of the present invention shown in FIGS. 7 and 8 is almost the same as the embodiment of the present invention shown in FIGS. The same reference numbers are given.

FIGS. 7 and 8 show a member or spring pin 144a which can be elastically bent. 7 and 8 show:
Although only one spring pin 144a is shown, it should be understood that a second spring pin corresponding to spring 146 of FIG. 4 is provided in association with spring pin 144a. The second spring pin has a structure similar to that of the spring pin 144a.

A resiliently flexible spring pin 144
a is the inner cylindrical surface 160a of the frame 150a of the stator 100a (see FIG. 8) and the outer cylindrical surface 1a of the tubular stem 108a forming the base of the electric motor.
62a. Although the electric motor is not shown completely in FIGS. 7 and 8, the electric motor is shown in FIG.
It should be understood that it has substantially the same structure as the electric motor 34 of FIG. Further, it should be noted that the tubular stem 108a is telescopically received on the electric motor stator 100a in a manner similar to that of the stem 108 of FIGS. 3 and 4 being received on the electric motor 34 stator. It should be understood.

The spring pins 144a (see FIG. 8) are disposed in straight grooves 166a and 168a formed in the stator frame 150a and the tubular stem 108a. The groove 166a is formed by a part of a cylinder having a larger diameter than the spring pin 144a that can be elastically bent. Thus, the center of curvature of the linear groove 166a is
It is shifted radially inward from the cylindrical inner surface 160a of the stator frame 150a. By making the groove 166a relatively large in diameter, the spring pin 144a has a linear contact area that is substantially in line contact with the stator frame 150a. The linear contact area between the spring pin 144a and the linear groove 166a extends parallel to the coincident central axes of the stator 100a and the tubular stem 108a.

Similarly, the linear groove 168a is formed by a part of a cylinder having a larger diameter than the spring pin 144a which can be elastically bent. Thus, the center of curvature of the linear groove 168a is offset radially outward from the cylindrical outer surface 162a of the tubular stem 108a forming the base of the electric motor. By making the groove 168a relatively large in diameter, the spring pin 144a has a linear contact area that is substantially in line contact with the tubular stem 108a. The linear contact area between the spring pin 144a and the linear groove 168a extends parallel to the coincident central axes of the stator 100a and the tubular stem 108a.

A resiliently flexible spring pin 144
“a” is formed by a part 200 (see FIG. 7) wound in a roll made of sheet metal. In an exemplary embodiment of the invention, the circular turns forming the spring pins 144a are wound in a spiral with adjacent turns abutting. Due to the abutted circular turns of the spring pin 144a, the spring pin has a generally cylindrical tubular configuration.

Prior to rolling the sheet metal part 200 (see FIG. 7) into a roll, the part has a flat rectangular shape. A sheet metal part 200 is wound in a roll shape, and has a cylindrical spring pin 1 having a plurality of circular winding portions and a central axis 204.
44a is formed. This spring pin 144a is
4 has a helical cross-section when viewed in a plane extending perpendicular to the direction of the cross section. The spring pins 144a have the same cross-sectional shape and size throughout the axial direction.

The spring pins 144a are inserted into the grooves 166a and 168.
a) to compress radially before inserting it into a. The pin 144a is then moved axially into the grooves 166a and 168a. Release pin 144a and release pin 1
The coiled winding of 44a expands under the action of its own natural elasticity. As a result, the outer winding portion of the metal component 200 is firmly pressed into the linear grooves 166a and 168a.

During operation of the electric motor corresponding to the electric motor 34 of FIGS. 2 and 3, the vibration force extending tangentially and radially to the cylindrical inner surface 160a of the stator frame 150a is elastically bent. Spring pin 144
Insulation is provided by the same spring pin associated therewith and corresponding to spring pin 146 of FIG. Accordingly, the vibration force reduced in the radial direction is transmitted between the stator frame 150a (see FIG. 8) and the tubular stem 108a forming the base of the electric motor.

An elastically deflectable member or spring pin 144a and an associated spring pin corresponding to spring pin 146 of FIG.
a and the effective transmission frequency of the structure formed by the tubular stem 108a. When the vibration force transmitted between the stator frame 150a and the tubular stem 108a during operation of the electric motor is reduced, vibration of the sheet metal housing connected to the manifold plate and the electric motor is reduced. By minimizing vibration, the amount of unpleasant noise during operation of the electric motor is greatly reduced.

In the illustrated embodiment of the resiliently deflectable member or spring pin 144a, the spring pin extends axially over a relatively short portion of the axial length of the stator frame 150a. Accordingly, a plurality of resiliently deflectable members or spring pins 144a are provided in the linear grooves 166a and 168a (see FIG. 8).
Thus, two or three spring pins 144a are provided in the straight grooves 166a and 168a. However,
If desired, the elastically deflectable member or spring pin 144a may be increased in axial length, with only one spring pin in each of the grooves 166a and 168a.

When the electric motor is operating and a vibrating force is applied to the elastically bendable member, ie, the spring pin 144a, the circular winding portion of the spring pin is elastically bent.
Due to this elastic bending of the winding portion of the spring pin 144a,
The outer diameter of the spring pin decreases. At the same time, the spring pin 1
The winding portion becomes elliptical due to the radial bending of the winding portion of 44a. The outer surface of the winding portion of the spring pin 144a and the groove 166a
And the linear contact area with the surface of 168a is relatively small and almost linear, so that when the spring pin is elastically deformed by vibrating force, the winding portion of the spring pin is moved relative to the stator frame 150a and the tubular stem 108a. Can shift slightly. If desired, the spring pin 144a
Very shallow grooves or depressions may be formed in the surfaces of the linear grooves 166a and 168a in order to keep them from moving axially.

In the embodiment of the present invention shown in FIGS. 7 and 8,
The spring pin 144a is a sheet metal rolled part 2
00 is formed. However, the spring pin 144a may have a different structure if desired. For example, the spring pin can be formed of an elongate rod or wire bent in a spiral.

From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.

[Brief description of the drawings]

FIG. 1 is a schematic exploded perspective view of an apparatus used for pumping hydraulic fluid.

FIG. 2 is a partial cross-sectional schematic diagram illustrating one particular embodiment of the apparatus of FIG.

FIG. 3 is an enlarged partial cross-sectional schematic view of a portion of FIG. 1 illustrating a method of placing a spring pin between a stator and a base of an electric motor formed in accordance with the present invention.

FIG. 4 is a schematic plan view, taken along line 4-4 of FIG. 3, showing the relationship between the frame, base, and a plurality of spring pins of the stator.

FIG. 5 is an enlarged partial view of one of the spring pins of FIG. 4;

FIG. 6 is an end view showing the structure of the spring pin, taken along line 6-6 in FIG. 5;

FIG. 7 is an enlarged sectional view of a second embodiment of the spring pin.

FIG. 8 is a schematic plan view, similar to FIG. 4, showing the relationship between the stator frame, base and spring pins having the structure shown in FIG.

[Explanation of symbols]

30 hydraulic fluid pumping device 32 pump unit 34
Electric motor 36 Drive shaft 38 Input shaft 40
Output shaft 42 Connector 44 Manifold plate 50
Hydraulic muffler 52 Reservoir 54 Housing 56
Inlet end 58 Channel 60 Outlet end 62
Aperture

Continuation of the front page (72) Inventor Michael A. Jones 90501, Torrance, Kota Avenue, California, USA 1015 (72) Inventor George Em Harpoul, 90505, Torrance, Riviera Way, California, United States 5602

Claims (33)

[Claims] 1. An electric motor, comprising: a base; a stator; a rotor rotatable with respect to the stator by an action of magnetic force transmitted between the stator; and a vibration between the stator and the base. An electric motor including a plurality of tubular spring pins disposed in engagement with the stator and the base to reduce transmission. 2. The rotor is rotatable about an axis extending through the stator, and a central longitudinal axis of each of the tubular spring pins is parallel to an axis about which the rotor rotates. The electric motor according to claim 1, wherein the electric motor extends. 3. Each of said tubular spring pins comprises:
The electric motor of claim 1, wherein the electric motor has a side wall at least partially defining a slot extending between opposite ends of the one spring pin. 4. The electric motor according to claim 1, wherein the spring pin elastically bends under the action of a force applied to the spring pin by the stator to change a cross-sectional shape of the spring pin. 5. The apparatus according to claim 1, further comprising an electric circuit connected to the stator and the base, wherein a rigidity of a connection between the electric circuit and the stator is significantly lower than a rigidity of the spring pin. Electric motor. 6. The electric motor according to claim 1, wherein the rotor at least partially surrounds the stator. 7. A drive shaft coupled to said rotor, said drive shaft extending through said stator and rotatable relative to said stator, said spring pin being radially outward of said drive shaft. The electric motor according to claim 1, wherein the electric motor is disposed on a side. 8. The first spring pin having a longitudinal central axis disposed in a plane extending through a central axis of the stator and a plurality of spring pins in a plane extending through the central axis of the stator. A second spring pin having a central longitudinal axis disposed therein, wherein the central axis of the stator comprises:
The electric motor according to claim 1, wherein the electric motor is disposed between the central axes of the first and second spring pins. 9. The electric motor according to claim 8, wherein the central axis of the first and second spring pins extends parallel to the central axis of the rotor. 10. Each of said spring pins is made of metal,
The electric motor according to claim 1, wherein the electric motor has a generally cylindrical shape. 11. The method of claim 1, wherein a portion of the base extends into the stator, and wherein the spring pin is disposed between the stator and a portion of the base extending into the stator. Electric motor. 12. The stator has a central longitudinal axis about which the rotor rotates, the base has a cylindrical portion extending axially within the stator, and the base has a cylindrical portion. The cylindrical portion has a longitudinal central axis coinciding with the longitudinal central axis of the stator;
The electric motor according to claim 1, wherein the spring pin is disposed between the cylindrical portion of the base and the stator. 13. A longitudinal central axis of the spring pin,
Extending parallel to the central longitudinal axis of the stator;
An electric motor according to claim 12. 14. The cylindrical portion of the base includes an inner surface that at least partially defines a passage extending axially through the base, the electric motor coupled to the rotor, and 13. The electric motor according to claim 12, further comprising an output shaft at least partially disposed within the passage of the base. 15. The magnetic force is generated by the interaction between stationary components arranged in a circular array on the stator and movable components arranged in a circular array on the rotor. The at least a portion of the base transmitted between the rotor and the stator is disposed in the circular array of stationary components provided on the stator, and the spring pins are provided on the stator. The electric motor of claim 1, wherein the electric motor is disposed in engagement with a portion of the base disposed in the circular array of arranged stationary components. 16. Each one of said tubular spring pins is formed by a member bent to form a plurality of turns about a longitudinal axis of said one spring pin. The electric motor according to claim 1. 17. The electric motor according to claim 1, wherein the spring pin is formed by a plurality of sheet members forming a plurality of circular winding portions. 18. The plurality of spring pins are formed by a plurality of sheet members, and each of the sheet members is
The electric motor of claim 1, wherein the electric motor is wound in a roll to form a spiral cross-section. 19. A base having a tubular section, a stator extending around the tubular section of the base, and extending around the stator and acting on the stator by a magnetic force transmitted between the stator and the stator. A rotor rotatable with respect to the rotor, a drive shaft rigidly connected to the rotor, extending through the tubular section of the base, and rotatable with the rotor relative to the stator and the base; And a bearing disposed between the tubular section of the stator and the stator for at least partially supporting the drive shaft for rotation relative to the tubular section of the base and the stator. The tubular section of the base to reduce transmission of vibrations to and from the tubular section of And a plurality of members which can be placed resiliently flex between the stator device. 20. The apparatus of claim 19, wherein the resiliently flexible member has a central longitudinal axis extending parallel to an axis about which the rotor rotates relative to the stator. 21. Each one of said resiliently deflectable members has a side wall at least partially defining a slot extending between opposite ends of said one resiliently deflectable member. 20. The device of claim 19. 22. The apparatus of claim 19, wherein said resiliently deflectable member is a tubular spring pin. 23. The apparatus of claim 19, wherein the central longitudinal axis of the plurality of resiliently deflectable members is located in a plane including the central longitudinal axis of the stator. . 24. The plurality of resiliently deflectable members include a first resilient member having a central longitudinal axis disposed in a plane extending through an axis about which the drive shaft rotates. A second elastically deflectable member having a central longitudinal axis disposed in the plane extending through an axis about which the drive shaft is centered about its rotation. 20. The drive shaft of claim 19, wherein the rotational axis of the drive shaft is disposed between the central axes of the first and second resiliently deflectable members.
An apparatus according to claim 1. 25. The apparatus of claim 24, wherein the central axis of the first and second resiliently deflectable members extends parallel to the axis of rotation of the drive shaft. 26. The elastically deflectable member is made of metal and has a generally cylindrical shape.
An apparatus according to claim 9. 27. The apparatus of claim 27, further comprising a pump unit coupled to the drive shaft and the base, and a housing extending around the pump unit and at least partially defining a reservoir. The member capable of reducing vibration transmission from the stator through the base to the housing;
The device according to claim 19. 28. The apparatus of claim 28, further comprising a housing coupled to said base and at least partially surrounding said rotor and said stator, wherein said resiliently flexible member is disposed between said stator and said housing. 20. The device of claim 19, wherein the device is effective in reducing the transmission of vibration through the base at the base. 29. The system further comprising a pump unit mounted on the base, wherein the drive shaft is connected to the rotor by a first end portion, a second end portion connected to the pump unit, and the second end portion. An intermediate portion extending between the first and second ends and at least partially disposed within the passage of the tubular section of the base;
The device according to claim 19. 30. The apparatus of claim 29, wherein the base includes a passage, and wherein during operation of the pump unit, fluid flow is directed through the passage. 31. Each one of said elastically deflectable members forms a plurality of turns about a longitudinal axis of said one elastically deflectable member. 20. The device of claim 19, wherein the device is formed by a bent member. 32. The apparatus of claim 19, wherein the resiliently deflectable member is formed by a plurality of sheet members defining a plurality of circular turns. 33. The elastically deflectable member is formed by a plurality of sheet members, each of which is wound into a roll to form a helical cross-section. 20. The device according to claim 19.